\documentclass{article}
%\usepackage{pgfplots}
%\pgfplotsset{compat=newest}
%\pgfplotsset{plot coordinates/math parser=false}
\usepackage{setspace,subfigure}
\usepackage{tikz}
\usetikzlibrary{plotmarks}
\usetikzlibrary{lindenmayersystems}
\usetikzlibrary{decorations.pathmorphing}
\usepackage{geometry}
\geometry{verbose=false,papersize={5.6in,5.6in},body={5.6in,5.6in},marginratio={4:3, 2:3}}% marginratio={horizontal ratio,verticalratio}
\begin{document}
\thispagestyle{empty}
\null\vspace{-10pt}
\hspace{0pt}
\begin{tikzpicture}[font=\Huge]
	\path[use as bounding box] (-4,-2.5) rectangle (15,9.4);
\node[blue] at (0,0) {\input{obj4o1}};
\node[green] at (5,0) {\input{obj4o2}};
\node[] at (0,5) {\input{obj4o3}};
\node[red] at (5,5) {\input{obj4o4}};
\draw[blue] plot[only marks,mark=*,mark size=0.5pt] file{obj4o1.txt};  
\draw[green] plot[only marks,mark=*,mark size=0.5pt] file{obj4o2.txt}; 
\draw[] plot[only marks,mark=*,mark size=0.5pt] file{obj4o3.txt}; 
\draw[red] plot[only marks,mark=*,mark size=0.5pt] file{obj4o4.txt};
\end{tikzpicture}
\end{document}
